Cluster Self-Organization of Intermetallic Systems: New Precursor Cluster 0@8(Sr2Au6) for Self-Assembly of the Crystal Structure of (Sr2Au6)(Ga3)-hR66

A combinatory-topological analysis and simulation of the self-assembly of the crystal structure of (Sr2Au6)(Ga-3)-hR66 (spatial group R-3c, a = b = 8.419, c = 21.911 angstrom, V = 1345 angstrom(3)) is performed by the computer methods (ToposPro software package). A new geometric type of the polyhedral precursor cluster K8 = 0@8(Sr2Au6), where Au-6 rings are the base and Sr atoms serve as peaks, is established. The symmetry of the K8 cluster corresponds to -3 and the center of the cluster occupies position 6b. Another cluster K3 = 0@Ga-3 also exhibits a close symmetry of 32 and the center of the cluster occupies position 6a. A primary chain S-3(1) is formed upon the binding of [(Sr2Au6)(Ga-3)](2) dimers. The distance between the centers of dimers appeared to determine the values of the modulus of the translation vector a = 8.419 angstrom. The symmetry and topological code of the self-assembly of the 3D structures from precursor clusters K8 and K3 are simulated.